In:
Scientific Reports, Springer Science and Business Media LLC, Vol. 7, No. 1 ( 2017-06-26)
Abstract:
In this study, genomic DNA was screened for novel Na + /H + antiporter genes from Halomonas zhaodongensis by selection in Escherichia coli KNabc lacking three major Na + /H + antiporters. Co-expression of two genes designated umpAB , encoding paired homologous unknown membrane proteins belonging to DUF1538 (domain of unknown function with No. 1538) family, were found to confer E. coli KNabc the tolerance to 0.4 M NaCl and 30 mM LiCl, and an alkaline pH resistance at 8.0. Western blot and co-immunoprecipitation establish that UmpAB localize as a hetero-dimer in the cytoplasmic membranes. Functional analysis reveals that UmpAB exhibit pH-dependent Na + (Li + , K + )/H + antiport activity at a wide pH range of 6.5 to 9.5 with an optimal pH at 9.0. Neither UmpA nor UmpB showed homology with known single-gene or multi-gene Na + /H + antiporters, or such proteins as ChaA, MdfA, TetA(L), Nap and PsmrAB with Na + /H + antiport activity. Phylogenetic analysis confirms that UmpAB should belong to DUF1538 family, which are significantly distant with the above-mentioned proteins with Na + /H + antiport activity. Taken together, we propose that UmpAB represent a novel two-component Na + (Li + , K + )/H + antiporter. To the best of our knowledge, this is the first report on the functional analysis of unknown membrane proteins belonging to DUF1538 family.
Type of Medium:
Online Resource
ISSN:
2045-2322
DOI:
10.1038/s41598-017-04236-0
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2017
detail.hit.zdb_id:
2615211-3
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